People living in neighborhoods with more green space may be less susceptible to CVD, according to a study published in the Journal of the American Heart Association.
The cross-sectional study consisted of 408 participants (median age, 51 years) recruited from a preventive cardiology clinic from October 2009 to December 2014 to study the relationship between residential greenness and biomarkers of CVD in susceptible individuals. The study measured biomarkers of CV injury and risk through blood and urine, which were collected with written informed consent, submitted between 1 to 4 p.m. to minimize circadian variability.
“Our analysis focused on comprehensive evaluation of risk factors as well as identification of underlying changes in catecholamines, circulating angiogenic cells and oxidative stress,” Ray Yeager, PhD, a research associate at the University of Louisville Diabetes and Obesity Center, and colleagues wrote.
Covariates such as age, sex, ethnicity and tobacco exposure were collected through participant questionnaires. CVD-relevant information was collected from questionnaires and medical information.
Of the participants (56% white; 39% black; 52% men), 75% were hypertensive, 60% hyperlipidemic and 61% at risk for CVD based on a Framingham Risk Score of more than 20%.
Researchers estimated greenness using satellite-derived normalized difference vegetation index (NDVI) in zones of a radii of 250 m and 1 km surrounding the participants’ residences. The researchers also adjusted for residential clustering, demographic, clinical and environmental variables.
In the fully adjusted models, NDVI levels within the 250 m were inversely associated with urinary levels of epinephrine (P = .006) and F2-isoprostane (P = .007). Researchers found stronger associations in NDVI and urinary epinephrine in women who were not on beta-blockers and did not previously experience MI.
Analysis identified of the 15 subtypes of circulating angiogenic cells examined, 11 were inversely associated (8% to 15.6% decrease per 0.1 NDVI) vs. two positively associated with contemporaneous NDVI (37.6% to 45.8% increase per 0.1 NDVI).
Because of the study’s cross-sectional design, causality of the link between greenness and CV health cannot be established, the researchers wrote.
“Although potential cofounders such as race, smoking, and sex were considered, these variables cannot fully account for nuances of socioeconomic status, environmental exposure and genetic variation, which likely could lead to residual cofounding,” Yeager and colleagues wrote. – by Earl Holland
Disclosures: The authors report no relevant financial disclosures.